The invention generally relates to telecommunications networks and more particularly to selecting sense point data and providing control for external devices.
Advanced Intelligent Networks (AIN) are modern telephone networks that separate call control from the actual trunk that carries the voice or data transmission of a call. In general, AIN Networks include a system in which the network queries a database to determine how a call should be processed once a set of call digits have been received from a phone. AIN Networks generally include three basic elements. A signal control point (SCP) is a computer controlled database that is for storing customer specific information that is used by the network to determine how to route and/or process calls. A signal switching point (SSP) is a digital telephone switch that is operable to communicate with SCPs and to obtain the customers specific instructions for processing the call. A signal transfer point (STP) is a packet switch that shuttles messages between the SSPs and the SCPs. All three, namely the SCP, the SSP, and the STP communicate via what is known as out-of-band signaling. Out-of-band signaling generally refers to the signaling that is for controlling a call. In other words, out-of-band signaling does not include the actual call data or voice information. Typically, the three described systems utilize a signaling system No. 7 (SS7) protocol or a variant thereof.
When a call is dialed, the SSP creates a query to the database within the SCP to find out how a call should be processed. The query is passed via out-of-band signaling through at least one STP to the SCP. The SCP interprets the query based on criteria within its databases and based upon information provided by the SSP. Once the SCP retrieves and transmits a return message through the STPs to the SSP, SSP may properly process the call within the network.
The STP is, in essence, a router for the SS7 network. It relays messages through the network but does not originate them. It is similar to a voice switch except that it only routes control signals. STPs also serve as gateway devices that may convert messages that flow between dissimilar systems. For example, an STP within the United States may provide conversions between ANSI SS7 and ITU-T SS7. STPs may also provide other functionality including various security functions and message filtering wherein messages of a non-conforming nature are not passed through from one point to another. Other STP functions include traffic monitoring for billing purposes and for developing usage statistics.
Facilities that house STPs often also include many different engineering and system maintenance activities. For example, there are many different types of devices that are often used within the vicinity of an STP. Test boxes, monitoring the equipment, environmental equipment, and the like, are often operating within close physical proximity to an STP. Each of these devices, however, typically are stand alone units whose operational status can not be readily controlled or monitored. Thus, a need exists, for an STP that integrates the control and monitoring of such stand alone pieces of equipment.
A signal transfer point (STP) includes a plurality of control and sense points that enable the STP to collect sensory information of all types and to provide control of individual pieces of equipment. Additionally, the STP is operable to generate reports that record the activity of external devices that are either being monitored or where operation is being controlled. Historically, a STP had sense and control point boards that were designed for very specific applications and whose control and sensing capability were quite limited. For example, the sense and control point boards were for monitoring systems within the STP. Herein the present invention, however, each sense and control point board provided within the STP is operable to provide up to 32 sense points (opto-isolator inputs) and twenty-four control points (relays) in one described embodiment of the invention. The sense points are operable to detect either a low voltage condition or a high voltage condition and are operable to monitor up to sixty volt signals. The system is specifically designed so that it may detect high voltage conditions, e.g., a logic one, in a US telecom network in which a logic one consists of a forty-eight volt signal or in Europe wherein a logic one consists of a sixty volt signal.